<p>Temporary urban greening may be especially valuable in dense cities where permanent greening is constrained by limited space, structural conditions, or competing land uses, yet its reception in different urban contexts remains insufficiently understood. This study examines user responses to “Mobile Green,” a movable tree-based greening system designed for temporary deployment on artificial ground. Questionnaire data were collected at three Japanese sites with contrasting visibility and surrounding green coverage: KK Line in central Tokyo, JR Sakuragicho Station Square in Yokohama, and Tsukuba Center Square in Tsukuba. The results indicated two complementary pathways. First, visibility-related site contrasts were associated with more favorable perceptions, particularly prominence and brightness, which were in turn linked to more positive evaluations. Second, lower-green-coverage sites were associated with stronger stated preferences for introducing Mobile Green into everyday settings such as workplaces and homes. By contrast, preference for event-oriented deployment was relatively stronger in the civic plaza context of Tsukuba, suggesting that site meaning and routine use are also related to how temporary greening is interpreted. These findings indicate that the value of Mobile Green is context-dependent and suggest its potential as a flexible, temporary, and adaptive public-space intervention within broader strategies of sustainable urban transformation.</p>